A340 AIRPROX - Delay in use of sidestick
Quote from me:
"RetiredF4 and DonH have identified the likely reason for the lack of sidestick action by either pilot. To be a bit more more specific, one or both pilots were probably trying to re-engage one of the two APs, possibly trying them both alternately. Many of us have seen this kind of behaviour: priority given to re-engaging the automatics, rather than flying the aeroplane."
Quote from DozyWannabe:
"I'd say they identified a *possible* reason, and acknowledged this at the time. To say it's a "likely" reason is objectively inaccurate - as we have no corroborating evidence to support the assertion, and subjectively unfair - as it assumes a degree of automation dependency on the part of the crew on the basis of anecdotal reporting (i.e. "Many of us have seen this kind of behaviour")."
From the AAIB Bulletin:
"The A340 commander's report
"...Shortly before the AIRPROX event he experienced moderate turbulence and noticed outside air temperature changes. Suddenly the aircraft began to climb, the Master warning soundedand the autopilot self-disengaged as the aircraft exceeded the speed limit of 0.86 Mach. The indicated airspeed dropped below VLS (the lowest selectable) as the aircraft climbed and the commander took manual control of the aircraft because neither autopilot would engage. The crew subsequently reported the incident to Shanwick on HF radio and, using their TCAS, they descended back to FL 360 in a safe area...
"The commander could not remember the sequence of warnings but he did recall being unable to re-engage either autopilot which prompted him to make manual inputs. He also remembered seeing an 'Alpha Lock' warning displayed on his Primary Flying Display."
My use of the word "likely", rather than "possible", was to specify my opinion. I cannot think of any other legitimate activity to explain the delay that we are discussing. It was not necessarily to imply what Dozy describes as "dependency"; rather that the crew prioritised re-engaging the AP during a period of time when the pitch attitude and flight profile were becoming abnormal, and clearly compromising the safety of the flight.